the Bate which has been mentioned I see was published by Schott (the Library of Congress has the 1951 miniature score).
Hrm, how about Andrey Arends' viola concertino (I see a piano reduction at IMSLP, I would have to seek out a full score if available...- well, it was published as Concertino pour alto-viola avec accompagnement de piano ou d'orchestre op.7, 1886, so it's not one of those student-concertinos whose accompaniment was always piano-only, certainly are those.)
Ah. Score and parts of the Arends at the Fleischer collection it seems - orch. for
solo viola, 2 flutes ,2 oboes, 2 clarinets, 2 bassoons ,2 horns, 2 trumpets (or 1 in the Ricordi edition?), timpani, strings.